Abstract: Apparatus for removing impurity substances in the air, comprising a first filter (17) for removing solid substances in the air flowing in a flow passage (13) defined by a housing (11); first cooling means (18) for cooling the air to not higher than its dew-point temperature; a wet-type impurity removing mechanism (19) for capturing gaseous substances in the air; second cooling means (20); and a second filter (22).

Abstract: Vacuum processing equipment capable of preventing particles from sticking to objects to be processed in vacuum vessels. The vacuum equipment comprises a series of vacuum vessels separated by doors, and the pressure in the vessels are reducible respectively. The vessels are so configured that objects to be processed are movable among them, and there is provided light projection means for projecting ultra rays on gases introduced to at least of the vessels.

Abstract: An apparatus for removing impurity substances in the air includes a first filter for removing solid substances in the air flowing in a flow passage defined by a housing; a first cooler for cooling the air to not higher than its dew-point temperature; a wet-type impurity removing mechanism for capturing gaseous substances in the air; a second cooler; and a second filter. The wet-type impurity removing mechanism includes a first liquid atomizer having a plurality of nozzle ports for spraying, arranged mutually spaced apart and facing each other in the direction of the air flow passage; first and second condensing and capturing assemblies located across the first atomizer and spaced apart from each other, with the first condensing and capturing assembly being upstream and the second condensing and capturing assembly being downstream from the first atomizer; a second atomizer for capturing any remaining gaseous substances in the air; and a third condensing and capturing assembly.

Abstract: A pair of jet nozzles are constructed for vapor-liquid contact removal in a gaseous molecule impurity removal apparatus, with one of the nozzles producing a counter flow to an upstream direction and the other nozzle producing a flow parallel to a downstream flow, the pair of nozzles being so disposed as to be joined together in a counter flow system. The counter flow nozzles are arranged alternatively so that they are not opposite each other. Also, a three stage eliminator structure is provided, and air that has been processed once is fed back to a central eliminator.

Abstract: A synthetic silica glass having a high transmittance for vacuum ultraviolet rays, for example F2 excimer laser beam with a wavelength of 157 nm, a high uniformity and a high durability and useful for ultraviolet ray-transparent optical glass materials is produced from a high-purity silicon compound, for example silicon tetrachloride, by heat treating an accumulated porous silica material at a temperature not high enough to convert the porous silica material to a transparent silica glass in an inert gas atmosphere for a time sufficient to cause the OH groups to be condensed and removed from the glass, and exhibits substantially no content of impurities other than OH group a difference between highest and lowest fictional temperatures of 50° C.

Abstract: Apparatus for removing impurity substances in the air, comprising a first filter (17) for removing solid substances in the air flowing in a flow passage (13) defined by a housing (11); first cooling means (18) for cooling the air to not higher than its dew-point temperature; a wet-type impurity removing mechanism (19) for capturing gaseous substances in the air; second cooling means (20); and a second filter (22).

Abstract: Vacuum processing equipment capable of preventing particles from sticking to objects to be processed in vacuum vessels. The vacuum equipment comprises a series of vacuum vessels separated by doors, and the pressure in the vessels are reducible respectively. The vessels are so configured that objects to be processed are movable among them, and there is provided light projection means for projecting ultra rays on gases introduced to at least of the vessels.

Abstract: An ion-exchanger is provided which comprises zirconium hydroxide supported on active carbon. The process for producing the ion-exchanger, and a process for removing a multiply charged anion are also provided which employ the ion-exchanger. The ion-exchanger of the present invention has high chemical resistance, high heat resistance, high mechanical strength, and excellent ion exchange characteristics.

Abstract: Described herein is a method for crystallizing aspartame (APM) by cooling an aqueous solution containing APM without forced convection during part of the crystallization, wherein a clear aqueous APM solution is initially cooled under forced convection and forced convection is interrupted, after crystallization has started but before the concentration of the APM crystals formed in the system reaches 0.5% by weight, until the amount of crystals reaches at least 10%, but not more than 50%, of the target amount, and wherein cooling is interrupted for at least part of the time of said interruption of forced convection at about the same time or shortly thereafter.

Abstract: A method for crystallizing .alpha.-L-aspartyl-L-phenylalanine methyl ester from a hot aqueous solution containing .alpha.-L-aspartyl-L-phenylalanine methyl ester by cooling is disclosed, which comprises (i) continuously supplying a hot aqueous solution of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a concentration such that the content of L-aspartyl-L-aspartyl-L-phenylalanine methyl esters is less than 0.6% by weight based on the weight of .alpha.-L-aspartyl-L-phenylalanine methyl ester in said solution, or if the content of L-aspartyl-L-aspartyl-L-phenylalanine methyl esters is 0.6% by weight or more based on the weight of .alpha.-L-aspartyl-L-phenylalanine methyl ester in said solution, to a crystallization vessel the temperature of which is lowered to that corresponding to the solubility of .alpha.-L-aspartyl-L-phenylalanine methyl ester or less, and (ii) continuously discharging the formed slurry from the crystallization vessel.

Abstract: A method for introducing an impurity into a polysilicon formed on an insulating film is described. A silicate glass layer (13) containing As is formed on a polysilicon layer (12) formed on an insulating film (2) and is thermally treated to introduce As into the polysilicon layer (12). The silicate glass layer (13) has a concentration of arsenic of not less than 25 wt. %, calculated as As.sub.2 O.sub.3 and the thermal treatment is effected in an atmosphere of a mixed gas of N.sub.2 and O.sub.2 with an oxygen partial pressure ratio of 0.05-0.7 at not lower than 1000.degree. C. for not shorter than 60 minutes.

Abstract: A method for forming a smooth borophosphosilicate glass film on a semiconductor substrate is described, in which a semiconductor substrate having at least one stepped portion thereon is formed with one side of the substrate a borophosphosilicate glass layer having a defined boron content and a defined phosphorus content with a defined total content of the boron and phosphorus. The layer is subjected to thermal treatment under conditions of a temperature of not lower than 940.degree. C. and a time of not shorter than 15 minutes in an atmospheric gas supplied at a flow rate of not lower than 19 liters/minute. As a result, the BPSG glass layer is smoothed on the surface thereof without formation of undesirable grains on the surface. This thermal treatment is particularly suitable for fabrication of a semiconductor element or device using an insulating film of the borophosphosilicate glass.

Abstract: A method of manufacturing a trench filled with an insulation material in a semiconductor substrate which includes the steps of forming a trench in the substrate, subjecting the substrate to an RF bias sputtering to form an oxide layer on the substrate, form a slope at an upper corner of the trench and produce a roundness at a lower corner of the trench, and filling the trench with the insulation material.

Abstract: A process for producing stable .alpha.-L-aspartyl-L-phenylalanine methyl ester, which comprises heat-treating crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of from 5 to 15% by weight based on wet crystals, at a temperature of higher than 50.degree. C. and lower than 80.degree. for at least 30 minutes.

Abstract: A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester having an improved solubility by drying wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester, characterized in that the wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester are granulated so that the specific surface area during the drying operation is at least 4 m.sup.2 /g, followed by drying.

Abstract: A process for producing dry .alpha.-L-aspartyl-L-phenylalanine methyl ester having an improved solubility from wet crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester having a water content of at least 20% by weight, which comprises drying the wet crystals at a temperature of higher than 50.degree. C. to obtain moist crystals having a water content of less than 20 and more than 15% by weight, then drying the moist crystals at a temperature of not higher than 50.degree. C. to obtain semi-dry crystals having a water content of less than 5% by weight, and further drying the semi-dry crystals at a temperature of higher than 50.degree. C. to obtain dry crystals of .alpha.-L-aspartyl-L-phenylalanine methyl ester.